I must strum you must strum he must strum we must strum you must strum they must strum
V-ing form
I must be strumming you must be strumming he must be strumming we must be strumming you must be strumming they must be strumming
Perfect
I must have strummed you must have strummed he must have strummed we must have strummed you must have strummed they must have strummed
V-ing perfect
I must have been strumming you must have been strumming he must have been strumming we must have been strumming you must have been strumming they must have been strumming
Negation
Simple form
I must not strum you must not strum he must not strum we must not strum you must not strum they must not strum
V-ing form
I must not be strumming you must not be strumming he must not be strumming we must not be strumming you must not be strumming they must not be strumming
Perfect
I must not have strummed you must not have strummed he must not have strummed we must not have strummed you must not have strummed they must not have strummed
V-ing perfect
I must not have been strumming you must not have been strumming he must not have been strumming we must not have been strumming you must not have been strumming they must not have been strumming
Interrogative form
Simple form
must I strum? must you strum? must he strum? must we strum? must you strum? must they strum?
V-ing form
must I be strumming? must you be strumming? must he be strumming? must we be strumming? must you be strumming? must they be strumming?
Perfect
must I have strummed? must you have strummed? must he have strummed? must we have strummed? must you have strummed? must they have strummed?
V-ing perfect
must I have been strumming? must you have been strumming? must he have been strumming? must we have been strumming? must you have been strumming? must they have been strumming?
Interro-negative form
Simple form
must I not strum? must you not strum? must he not strum? must we not strum? must you not strum? must they not strum?
V-ing form
must I not be strumming? must you not be strumming? must he not be strumming? must we not be strumming? must you not be strumming? must they not be strumming?
Perfect
must I not have strummed? must you not have strummed? must he not have strummed? must we not have strummed? must you not have strummed? must they not have strummed?
V-ing perfect
must I not have been strumming? must you not have been strumming? must he not have been strumming? must we not have been strumming? must you not have been strumming? must they not have been strumming?